Jetpack: Shortcode: Presentations: Revert r803113 which undid a fix 
during a merge! Oops!

Resolves NOTICE: UNDEFINED INDEX: FADEBULLETS IN 
WP-CONTENT/PLUGINS/JETPACK/MODULES/SHORTCODES/PRESENTATIONS.PHP 
ON LINE 306


git-svn-id: https://plugins.svn.wordpress.org/jetpack/trunk@809151 b8457f37-d9ea-0310-8a92-e5e31aec5664